Imaging device for recognition and method of controlling the same

1. An imaging device for recognition including an image pickup unit that sequentially generates a plurality of images by shooting an object, an object recognition unit that recognizes, in each of the plurality of images, an object region in which the object is located in the image, and a tracking unit that tracks the object region across the plurality of images, said imaging device for recognition comprising: an area calculation unit configured to calculate an area of the object region; and an exposure control unit configured to set a first exposure time for the image pickup unit in the case where the area is smaller than a first threshold, and to set a second exposure time longer than the first exposure time in the case where the area is equal to or larger than the first threshold, wherein said exposure control unit is configured to set the first exposure time in the case where a resolution for recognition proportional to the area and inversely proportional to a motion blur in the object region is lower than a second threshold, and to set the second exposure time in the case where the resolution for recognition is equal to or higher than the second threshold.

2. The imaging device for recognition according to claim 1 , further comprising a moving speed calculation unit configured to calculate a moving speed of the object region; wherein said exposure control unit is further configured to set a third exposure time in the case where the moving speed is lower than a third threshold, and to set a fourth exposure time shorter than the third exposure time in the case where the moving speed is equal to or higher than the third threshold.

3. The imaging device for recognition according to claim 1 , further comprising a light amount calculation unit configured to calculate a light amount in the object region, wherein said exposure control unit is configured to set a fifth exposure time for the image pickup unit in the case where a light amount for recognition proportional to the area and to the light amount is equal to or larger than a fourth threshold, and to set a sixth exposure time longer than the fifth exposure time in the case where the light amount for recognition is smaller than the fourth threshold.

4. A method of controlling an imaging device for recognition including an image pickup unit that sequentially generates a plurality of images by shooting an object, said method comprising: recognizing, in each of the plurality of images, an object region in which the object is located in the image; tracking the object region across the plurality of images; calculating an area of the object region; and controlling an exposure of the image pickup unit so as to set a first exposure time in the case where the area is smaller than a first threshold, to set a second exposure time longer than the first exposure time in the case where the area is equal to or larger than the first threshold, to set the first exposure time in the case where a resolution for recognition proportional to the area and inversely proportional to a motion blur in the object region is lower than a second threshold, and to set the second exposure time in the case where the resolution for recognition is equal to or higher than the second threshold.

5. A non-transitory computer-readable recording medium comprising a program configured to cause a computer to execute said method according to claim 4 .

6. A semiconductor integrated circuit comprising the image pickup unit, the object recognition unit, said tracking unit, said area calculation unit, and said exposure control unit according to claim 1 .